Continuous hot mill



H. G. OBRIEN.

CONTINUOUS HOT MILL. APPLICATXQN mm SEPT. 4. 1919.

1 325,537 Patented Aug. 15, 1922 I 2 Q {3- A2511 i 2 Ew-E'a 5 k 2 5--EEP UNITED STATES PATENT OFFICE.

HENBT G. 0mm, 0F Wm, OHIO, ASSIGNOB TO THE TBUKBUXJ: S'l'm comm, OPWARREN,- O ID, A CORPORATION 01! OHIO.

oozrrnwous 301' um.

of wider range, in the matter of thickness.

particularly, than otherwise can be got from a single mill installation,and this with v greatest economy of speed, power, and floor space.

Understanding of the invention will be aided .by reference to theaccompanying sheet of drawings which shows diagrammatically and in plana mill installation such as may embody my invention.

The mill so diagrammatically shown (a strip mill-though in thisparticular respect my invention is not limi ted-it might be a bar millor a rod mill) consists of thirteen roll stands, indicated by thesuccessive numerals 1 to 13. Of these the first seven roll standsconstitute, in mill parlance, the roughing rolls or the roughing mill(using the word mill in a more particular sense than when applied to theentire assembly), and the last four constitute the finishing rolls orfinishing mill. The two intermediate roll stands, 8 and 9, stand apart,as will resently appear, in respect to the mode of driving, but suchsegregation of these two stands is not essential to m invention in itsbroader aspects.

Heretofore the sucoemive rolls of continuous mills have ordinarily beendriven from a common motor; in some instances the roughing rolls and thefinishing rolls have been grouped. each group apart. and each driven asa group from one motor: it has even been proposed to drive each separateroll stand of a continuous mill by a motor f its own. But neverheretofore. so far as I know, has it been proposed to drive a continuousmill as I drive it.and herein is the fundamental characteristic of myinvention: l group the several stands of roughing rolls together anddrive the group by one motor:" or perhaps. and as the drawingsSpecification of Letters Patent G. OBmaN,

' Patented Aug. 15, 1922..

Application fled September 4, 1919. Serial No. 321,680;

in 1 a plurality of groups and drive each group by a single motor; andthen, respectr mg the stands of finishing rolls, I drive each roll standby a separate motor.

By such an arrangement I have the economies of the group arrangementwhere it is altogether advantageous.at the roughing end, namely, of themill; and I have the advantage of separate drive, where separate driveis advantageous, that is, at the finishing end of the' mill. Separatedrive of the several roll stands of the finishing rolls is advantageous.in that the mill is made flexi ble in adapability to a product ofvarying gauge.

Referring to the drawing, a succession of roll stands 1 to 13 is shown,on the line of rolling A-B, the direction of the advance of the materialunder operation being indicated by the arrow 0. The grou of roll stands1 to 7 inclusive. at the roug ing end of the mill is driven by a singlemotor 14; a second and intermediate group, consisting of the twohorizontal roll stands 8 and 9 (which may be termed roughing rolls orintermediate rolls), may be driven by a single motor 15; while the fourroll stands l013 inclusive at the finishing end of the mill are driven,each by a separate motor, 16-19 inclusive.

As indicated in the drawing, standsQ, 3, 5, and 6 of the roughing millare stands of horizontally placed rolls, for fiat rolling, while stands1, 4and 7 are edging passes. The rolls of these edging passes may ifdesired. be driven by means other than motor 14.

It should be remarked too that the motors 16-19 (and motors 14 and 15also. if desired) are conveniently variable-speed motors.

Conliningattention next to the roll stands at the finishing end of themill, and to their more minute construction, I find it advantageousandthis feature, though not in itself alone a part of my present invention,is, when combined with the roll-driving arrangement already described, aconsequent advantage- (for in such combination the flexibility of themill, already alluded to is greatly enhaneed)-l find it advantageous toconstitute the final roll stand 13, and preferabl the next to last stand12 also a frictiou roll pass: a roll pass, that is to say, in which oneof the pair of rolls and only one is positively driven. the companionroll turning by friction as work progresses becentrated within a s5 theuse of which the tween the two rolls. And, further, Ipreferably'superadd to such friction-roll or' roll passes the inventionof United States Letters Patent, N 0. 1,336,177, granted to JosephWithers and myself, April 6th, 1920,the invention, namely, of positivelydriving the idle member of the roll pair, in case its rate of turningunder the normal impulse by friction is arrested or falls below acertain predetermined speed.

F inall and herein lies a further consequent a vantage of my invention,I make the final roll stand, or the rolls thereof, and if preferredother stands of finishing rolls or the rolls thereof, removable andreplaceable.

Heretoforesheet or strips of a certain thickness requiring certainlimitation in roll dimensions, have imposed corresponding limitations onany given mill, and no mill could produce sheets or strips of thicknessother than its rolls, because of their dimensions, were adapted toproduce. If, for example, it be a strip one ei hthof an inch inthickness which is to be rolled, the friction roll (that is'to say, orlinarily, the upper roll) of each finishin roll-pass must be atwelve-inch roll; but, if strip of liner gauge be required, twelve-inchrolls willbe inadequate to produce it. There is need for rolls ofsmaller diameter (ten-inch rolls, say) in pressure in the roll pass uponthe metalunder operation will be consmaller area; furthermore,twelve-inch rolls are ordinarily made of such length of barrel that thefgive or springiness" will 'render the rollin o'f liner gauges uncertainand inaccurate. T ierollin of stri of. gauges finer than one eighth ofan inch has heretofore required a se arate and distinct mill, for thosegau es on or, as-has been more common! t e case, the liner gauges havebeen pro need by subsequent cold-rolling of the previously rolled'rality of finishing-roll stands,

my hand.

one'eighth material-and has been accomplished at creased cost.

Now, by

that, of course, appreciably inproviding separate motors for the severalpasses of finishing rolls, and particularly by providing variable speedmotors for driving the rolls of the several passes, new possibilitiesopen; I can then make my several roll passes removable and replaceable,and, ado ting alternate roll passes of rolls of difiiirent sizes (ofsuch dill'erent sizes, for example, as above su gested) I can render myimproved nil flexible as no other mill known to me is flexible, and canin one and the same mill, with the adaptations described. roll materialof wider range in dimension than has hitherto been achieved.

Thus in selecting and combini these several features of millconstruction attain not merely the several benefits known to beattributable to them, but. more than that I attain a mill of economiesand capacities never before attained, within my knowledge.

It will be understood that my invention to details of number andarrangement, but is broadly attained in the arrangement herein claimed.

I claim as my invention:

A hot mill for rolling metal including a plurality of roughing-rollstands and a plua common motor driving the rolls of the severalroughing-roll'stands, a plurality of-motors corresponding in number withthe finishingroll stands and connected 0 rativel ly, one to each of saidFinishing-r01 stands. 1.

In testimony whereof I have hereunto set HENRY G. (JBRIEN Witnesses:

I)AUL N. (lin'roHLow,

FRANCIS J. TOMASSON.

